Bump regex from 1.4.3 to 1.4.4 (#506)

Bumps [regex](https://github.com/rust-lang/regex) from 1.4.3 to 1.4.4.
- [Release notes](https://github.com/rust-lang/regex/releases)
- [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md)
- [Commits](rust-lang/regex@1.4.3...1.4.4)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>